test: add internal/fs tests
- add tests of
internal/fs.js
- increase coverage
move tests ofrequire(internal/fs).stringToFlags
intest-fs-open-flags.js
totest-internal-fs-string-to-flags.js
for a more accurate and findable filename
Checklist
-
make -j4 test
(UNIX), orvcbuild test
(Windows) passes -
tests and/or benchmarks are included -
commit message follows commit guidelines
Affected core subsystem(s)
test